Among the greatest mysteries of the tropical rainforest are the pooping habits of sloths. Really. Those furry, slow-moving tree dwellers almost never descend from the safety of the tree tops—except ...

While humans wouldn’t be very happy to find that organisms were growing on their skin, particularly fungi, algae, and insects, it works out pretty well for sloths. Sloths may be hosting entire ...

"First, we have to understand where colours in animals come from," says Kjetil L. Voje. He is an evolutionary biologist and ...

Sloths are famous for moving slowly, but that extreme pace has unexpected biological consequences. Because they spend so much ...